I just happen to know for a fact that as it's got a single 12v rail, it's more than likely that it can run 2x GTX 670.

Example: my i7 920 is a C0, and breaking the 3.8GHz barrier takes quite the voltage increase, just to reach 4.0. That's a C0 for you. So that's some extra power consumption there. Back on topic:

Now, I also just got an eVGA GTX 670 FTW. And it just so happens my brother, whom I'm building a rig for once the last few parts arrive, has gotten the exact same card. Now as they've both arrived before the other parts, we decided to test them in SLI in my rig for a day - just for kicks.

Turns out my 650 watts Corsair TX650 is more than capable of handling them both at once. Tried it in Battlefield 3 maxed for hours, tried it in Hitman: Absolution, and Far Cry 3 - even Heaven benchmark 3.0. All maxed of course. It's also got a single 12v rail, with 56 amps on it (something like that, can't remember exactly) - which in this case is plenty to run two 670 FTW Editions at once, along with an overclocked i7-920 C0.

So judging from my own experience, the PSU that you linked should be able to handle it just fine, as it's also only got a single 12v rail (can't find out how many amps it's on, but I'd imagine 60-62ish?), is the same brand (Corsair), and is in theory capable of handling 50 watts more than mine. I obviously can't take any responsibility if your results vary, but I highly doubt it.

People overrate wattage big-time, and most often underrate the significance of amps on the 12v rail(s).